A novel 4-aminobenzyl ester-based carboxy-protecting group for synthesis of atypical peptides by Fmoc-But solid-phase chemistry

4{N-[1-(4, 4-Dimethyl-2,6-dioxocyclohexylidene)-3-methylbutyl]amino}benzyl ester (ODmab) is a new carboxy-protecting group that is based on the safety-catch principle and can be used orthogonally with Fmoc-Butpeptide chemistry, but is completely removable with 2%v/v hydrazine·H2O-DMF at room temperature within minutes.